Clear release notes (#1077)

Author: llucax

RELEASE_NOTES.md

@@ -1,5 +1,17 @@
 # Frequenz Python SDK Release Notes
 
+## Summary
+
+<!-- Here goes a general summary of what this release is about -->
+
+## Upgrading
+
+<!-- Here goes notes on how to upgrade from previous versions, including deprecations and what they should be replaced with -->
+
+## New Features
+
+<!-- Here goes the main new features and examples or instructions on how to use them -->
+
 ## Bug Fixes
 
-- `ConfigManagingActor`: Fixed an issue where the actor was unable to process events after being restarted.
+<!-- Here goes notable bug fixes that are worth a special mention or explanation -->